On Your Mind
by suicidalunicorn97
Summary: Post 12x15, Sam is worried about Dean, so he calls Cas. Destiel fluff. Rated T for language. Trigger warning for PTSD.
1. Chapter 1

Sam dialed Cas's number twice before he actually let the call go through. He felt stupid; probably seeing a problem where there wasn't one...but this was Dean. If his brother was in trouble, he had to do something about it.

 _"Hello?"_

"Hey Cas."

 _"Sam, is everything alright?"_

He frowned at angel's slightly panicked tone. "Calm down, Cas...why wouldn't it be?"

" _I'm sorry. It's just, I talked to you and Dean less than four hours ago. Two calls in one day...either you have news about Lucifer's spawn, or you're in danger."_

"No, we're not in any immediate danger." Sam assured. He felt bad as he realized Cas was right. They never called just to talk, or check in. They usually only initiated contact with him when they needed something.

"Sorry if I interrupted anything, are you busy?"

" _Not right at this moment. Do you need assistance?"_

"No, I just...wanted to talk about Dean. I'm kinda worried about him."

 _"Why? What's going on?"_

"It's probably nothing to worry about, I've just noticed some old habits coming back."

 _"I don't understand."_

"He's doing the _thing_ again. The thing where he just sort of...stops taking care of himself. Working cases back-to-back without taking time for a rest, even a shower...a couple days ago we got home from a hunt and he hadn't changed his clothes for _four_ days. He insists on doing all the driving, he doesn't let me take over so he can sleep. He's drinking again. I mean, he never really stopped, but it's getting excessive."

 _"That is concerning."_ Cas agreed. " _But I've noticed he exhibits these behaviors during times of emotional turmoil. The situation with your mother probably isn't helping."_

"Yeah, but it seems worse than usual...I'm honestly a little afraid to leave him alone tonight."

 _"Why?"_

"Today was just...a really shitty day for him. We worked a case with a rogue Hellhound, first of all."

 _"Dean hates them."_

"That's an understatement. I know it's been years, but sometimes I can just _see_ it in his eyes, you know? Like he's remembering."

" _Being torn apart by Hellhounds is not something you forget."_ Cas murmured.

"Yeah, also..." Sam hesitated. "I've sorta been working with the British Men of Letters."

 _"What?"_ Cas asked, clearly surprised.

"I know...and it's not like I trust them; I still hate them. But they've been sending me cases, and it's not like I can just ignore the fact that there are real people in danger that I could help."

Cas was quiet, so Sam continued. "Anyway, I've been keeping it a secret from Dean, but I finally told him today."

 _"How did he take it?"_

"Shockingly well. It was weird, he just said, 'okay.' He didn't yell, kick me out of the Bunker, or anything. He didn't even look surprised."

 _"Dean is often more observant than you give him credit for. I'm sure he's suspected it."_

"I guess I hadn't thought about that...but his reaction was still weird. A kind of tired acceptance, like he's just given up. He told me I was _right._ That's not how I expected this to go down. He just let it go without a fight; said we could give them a chance."

 _"That is unusual, considering he kicked your mother out for the exact same thing less than a month ago."_

"Right? That's what I thought. I mean, I'm glad he didn't freak out. I am. The last thing I want is for things to go bad between us; I hate it when we fight. But-"

" _But you think it's more than that."_

"Exactly. And I don't think he's gonna talk to me about it. He's probably still pissed at me, whether he's showing it or not. So if you get a chance, maybe you could just swing by and talk to him...maybe he'll open up to you."

 _"I can be there tomorrow."_

"Thanks, Cas."


	2. Chapter 2

Cas hung up the phone, wishing for the thousandth time that his wings were functional again. Driving across the country was extremely inconvenient. He wanted to be there for Dean _now._

He turned to Joshua. "I'm sorry, I had to take that call."

The Gardener smiled. "Don't worry, I understand. The Winchester are your family as much as we are; possibly even more so."

Cas looked down, not sure how to respond to that. When Sam had asked if he was busy, he should've said yes. He was meeting with one of Heaven's oldest angels, discussing his possible redemption. But he could tell by the younger Winchester's voice that something was wrong.

"So what are your thoughts on helping us find Kelly Kline?"

"I'll do it." He said, not even having to think about it. "It's what I've been doing for months, I don't see how it will be different."

"Mostly communications. It helps to have eyes all over. But our soldiers are so inexperienced in comparison to you; with Dagon protecting the girl, they will need your guidance."

Cas nodded. "I will be there when we locate Dagon and Ms. Kline."

"But you do not agree with our methods."

"I don't want to kill the woman, no."

"But surely you understand the danger of allowing her to live?"

"Of allowing her _child_ to live." Cas delicately corrected. He meant no disrespect to Joshua. The Gardener was one of the few angels who did not want to see Castiel dead or imprisoned.

"We will do what we can." Joshua sighed. "But you know what it may come down to. She is only a mortal, after all. Her body is not designed to handle Lucifer's spawn. I am certain that she would die in labor anyway."

"Before anything, we have to find her." Cas said, not wanting to discuss this further.

"Yes. But it seems as though you will be unavailable for the next day or so."

Cas shook his head. "If we manage to find Kelly, the Winchesters will come with us to fight Dagon."

"Good. We could certainly use all the help we can get, even if they are only human." Joshua's eyes twinkled. "You should go to them. I can sense your concern for Dean Winchester."

"Thank you for your patience and understanding." Cas said sincerely.

"It is no secret what he means to you." The older angel said. "His soul longs for you, even now. The profound bond you share runs deeper than you know."

Before Cas could ask what that meant, Joshua was speaking again. "I can get you there by tonight, if you'd like."

He squinted. "But all the angels...since the fall, our wings...we cannot-"

"I have a few tricks up my sleeve." Joshua smiled. He simply snapped his fingers, and suddenly Cas was outside the Bunker.

* * *

His head was spinning. How did the Gardener know where the Bunker was? He felt slightly dizzy. Had it been a spell? Most likely.

Shaking his head to try and clear the discomfort, he knocked loudly before entering.

He was met with the usual sight; (guns pointed at his chest) before Sam and Dean realized it was him and lowered their weapons.

"Cas?!" Sam's eyes widened. "I thought you were in Idaho! How'd you get here so fast?"

The angel descended down the stairs, letting his gaze fall on Dean. Sam was right. There was something...off. He could feel it. "I was in Idaho. And then I made a stop at the Portal to talk to Joshua. He performed a spell of some sort to get me here."

The brothers stared at him in shock. "You...went back to Heaven?" Dean blinked. "I thought they shut you out. And Joshua...I haven't heard that name in a long time. I assumed he was dead or something."

"He doesn't like to interfere with the affairs of men. But this is an 'all hands on deck' situation, as they put it." He quickly explained how they wanted his help to find Kelly Kline.

"Wow. So, what, you help them and then they just forget about everything you've done?" Dean raised an eyebrow. "E.T. goes home, huh?"

Cas shook his head sadly. "That is what Joshua promised, but I don't think it's possible. Every angel in Heaven knows what I've done. Most of them hate me. An official pardon from Joshua would stop them from trying to kill me, but it would never be the same. Heaven is not my home."

"That's okay," Dean patted him on the shoulder. "You've got a home right here."

"Thank you." Cas said, although he didn't look convinced. Truthfully, he didn't feel like he belonged anywhere.

"So, what's up? Don't get me wrong, I'm happy you're here, man. It's just kinda out of the blue." Dean sat down, tossing him an extra beer.

Cas knew Dean would shut down if he knew Sam had orchestrated this. "I missed you." He said. It wasn't a lie. He could feel Dean's unconscious longing for him, and found himself constantly thinking about the hunter as well.

Dean almost choked on his drink. "O-oh." He stuttered.

Sam grinned. "I'm going to bed." He chuckled. "Nice to see you, Cas."

"Goodnight, Sam."

* * *

 **Thanks so much for reading! Please leave a review if you liked it. I should have the next chapter up by tomorrow :)**


	3. Chapter 3

"Dude, you can't just say stuff like that." Dean was blushing ever so slightly.

"Why not? It's true, Dean. I missed you. And Sam, of course." Cas added, turning his head. But the younger Winchester was already out of sight.

"Whatever." Dean muttered. He took a sip of his beer. "So how've you been?"

"Fine." Cas fidgeted with his own drink, unsure how to proceed. "How are you?"

"Doin' great." Dean smiled, but it didn't reach his eyes.

"No, you're not." The hunter's brow furrowed, as if he was about to argue. "Dean, there is something weighing heavily on your mind. I can feel it."

"Get outta my head." Dean said, setting his beer down a little harder than necessary.

"I'm not 'in your head'. I am not reading your mind. I'm simply making an observation."

"What, so you can 'feel' my thoughts now?" Dean scowled.

Cas sighed in exasperation. "Like it or not, we are connected. I can sense the darkness clouding your mind, and it worries me."

"I'm fine."

"You can be maddening sometimes." Cas rubbed his temples. "I am simply trying to help."

Dean had the decency to look guilty. "Sam is working with the British Men of Letters." He finally said.

Cas tried to look surprised. "Oh?"

"Yeah, the same dirtbags who tortured him. I don't know how he's okay with this. I'm fuckin' pissed."

"Then why have you not kicked him out?"

Dean looked at him like he'd lost his mind. "It's _Sam!_ He's my brother."

"I'm just trying to understand...I am glad you have decided not to part ways with Sam. But I'm confused; you told your mother to leave when she was doing the same thing."

If it had been anyone else, Dean surely would have been throwing punches by now, not explaining himself. He shook his head. "I dunno, man. I've been watching out for him since I was a kid. I can't..."

"You can't let him go." Cas nodded, understanding.

Dean laughed bitterly. "After all these years...I still can't stand the thought of being alone." He admitted, showing uncharacteristic vulnerability.

"You're not alone." Cas leaned forward. He wanted to _touch_ Dean. To comfort him. But he didn't want to ruin the moment. One wrong move, and the hunter would shut down again.

"But I would be if I lost Sam to the Brits." He took a drink. "I'm way too sober to be having this conversation."

"Dean, you wouldn't be alone. I will always be here." Cas said, hurt that the hunter seemed to have forgotten about him.

"You're an angel. You've got your own shit going on. I mean, your family is rollin' out the welcome mat; taking you back. Once you can go back to Heaven, I don't know why you'd ever wanna come back to this shitty planet."

Cas glared. "I told you; I am not _welcome_ in Heaven. It isn't my home anymore. And they are _not_ my family." He angrily stood up. "I'm sorry, I was under the mistaken impression that I had a home here. That you and Sam were my family. Unless that has changed in the last ten minutes."

Once again, guilt-ridden green eyes stared up at him in shock. Dean clumsily stood and grabbed his arm. "Please don't go." He swallowed hard. "I'm sorry, I didn't mean it."

Cas blinked. He couldn't remember the last time Dean had apologized like this.

"This _is_ your home. You're family, Cas. I guess...I guess I just have a hard time seeing why anybody would wanna stay with me."

The angel put a hand on Dean's shoulder, where the mark of his handprint used to be. The touch sent a spark of electricity through him, and he wondered if Dean felt it too.

"How can you think so little of yourself?" He asked sadly.

"Everyone leaves in the end." Dean shrugged. "Other than Sam, no one's stood by me this long. I don't know why you're still here."

"Because I care about you!"

Dean exhaled sharply, and leaned in to Cas's touch as if those words had shaken him deeply. And maybe they had.

"Dean Winchester, you are worth more than you know. I meant what I said in that barn. Knowing you has been the best part of my life. And I am very old."

The hunter tried to smile. "Thanks, Grandpa."

Cas rolled his eyes. "You should go to bed. I can sense your exhaustion."

Dean weakly protested as Cas followed him to his room. The angel stood in the doorway.

"Will you...still be here in the morning?"

"If you'll let me stay, I would be happy to." Cas nodded.

"Yeah. I know you don't sleep, but you can hang out in the library or something. Wake me up if you get bored."

* * *

Cas wandered to the library, turning on a single lamp. He sank into a chair. Dean's mind really was in bad shape. He wished there was something he could do to help; anything. Perhaps if he admitted the true nature of his feelings for the hunter...

No.

It could ruin their friendship. Dean would never want him in that way. He could sense the hunter's love for him, but getting Dean to realize it was more than platonic would be impossible.

Castiel closed his eyes. Being so close to Dean, feeling the mutual yearning for each other...and not being able to run to him...was like torture. But he would respect Dean's personal space, as he wished.

An few hours passed, and there was a slight change of energy.

Cas could feel Dean's soul calling out for him. Begging for help.

 _Fear._

Dean was in trouble.


	4. Chapter 4

Cas raced to Dean's room, expecting to see some sort of fight; an intruder perhaps. But instead he found the hunter asleep, clearly in the throes of a nightmare. His fists were clenching the sheets, brow shining from perspiration. His face was contorted as if in pain, but the only sounds he made were tiny whimpers.

If it wasn't for the bond they shared, Cas never would have known Dean was suffering silently.

"Dean," Cas turned on the lamp and sat at his bedside, gently shaking his shoulder.

The hunter gasped, sitting straight up. His eyes opened wide and Cas could see the terror fade as Dean recognized that he wasn't in danger.

"Cas?" He ran a hand through his hair. "W-what are you doing here?"

"You were having a nightmare." The angel explained.

"Sorry." Dean cleared his throat. "I hope I didn't wake Sam up."

"No, you were being very quiet."

"Then how-?"

"I could feel it."

"Of course you could." Dean rubbed his eyes.

"What were you dreaming about?"

Dean almost told him to buzz off; that it was none of his business. But the way his friend was looking at him...worry in those kind blue eyes...he couldn't bring himself to lie.

"Hellhounds." He shuddered, even saying the word. "The case we worked...there was a Hellhound..." He couldn't even finish a sentence. Just thinking about those glowing red eyes, shadowy figure, and razor sharp claws...he couldn't breathe.

"Dean!" Cas put one hand on his shoulder, and the other grasped his hand. "You need to calm down."

"Easy...for you to...say..." He wheezed.

"It's okay," Cas squeezed his hand. "Breathe...You're safe. They can't hurt you anymore."

"I know," His breathing was slowly returning to normal, but he was shaking. Trembling like a leaf in the wind. "It's just, s-sometimes I can still feel their breath on my neck, their...c-claws in my chest." He stuttered.

Cas frowned, then stared at Dean's chest thoughtfully. Their hands were still intertwined, and Cas slowly moved them up under Dean's shirt. The hunter flinched, but didn't pull his hand away. "What are you doing...?"

"Do you trust me?"

Dean nodded, a blush creeping up on his freckles.

With Cas's hand on top of his, the angel slid their hands up his chest to rest above his heart.

"Do you feel that?" He murmured.

"My heartbeat...?"

"Smooth skin. No claw marks. Healthy, beating heart. You're alive, Dean."

The hunter drew a quivering breath. "Yeah,"

Cas let go of his hand, and Dean coughed awkwardly. "So, um, can you 'feel' it every time I have a nightmare?"

"Most of the time, yes. It seems to be a frequent occurrence for you, especially lately."

"Jesus, I'm sorry, man." Dean looked away.

"It's alright. I just wish I was here to help you every night."

Dean met his gaze, expression unreadable. But Cas could feel his soul aching for contact; for comfort. Subconsciously, Dean wanted Castiel to be there.

"I could be, you know." He said quietly, studying Dean's face carefully to gauge his reaction.

"You're always welcome here at the Bunker, Cas. We could make up one of the spare rooms, and-"

"I don't sleep."

"I know, but it's kinda nice to have your own space."

"Or...I could stay here in your room. Watch over you."

Cas waited for Dean to tell him 'no fuckin' way,' and that it was 'creepy', like the last time he'd mentioned it. But he didn't. He was silent for a moment, and then replied, "You would do that for me?"

"Of course."

Dean rubbed the back of his neck. "I dunno, it might be kinda boring."

"Watching you is never boring," The angel assured.

"Does that mean you do it often?" Dean smirked.

It was Cas's turn to blush. "You should try to sleep again."

Dean looked uncertain. "Every time I close my eyes...I see them. The Hellhounds."

"I'll be here." Cas repeated. He reached to turn out the light, but Dean stopped him.

"Could you leave it on?" He asked sheepishly.

"Of course."

Dean reluctantly laid back down, but didn't close his eyes. "Cas?" He asked, suddenly sounding very small.

"Yes, Dean?"

"It, uh, helps when you touch me. Would you mind...?" He slid over, making room for Cas to lie next to him on the bed.

"Are you sure?" The angel's heart jumped at the opportunity, but he didn't want to make Dean uncomfortable.

"Please,"

That's all it took. Cas kicked off his shoes and removed his overcoat before climbing into bed, facing Dean.

"What?"

Dean was staring at him with an unmistakable look in his eyes. "Nothing," He licked his lips. "That was just, uh, way hotter than I expected it to be." He chuckled nervously. "Sorry,"

"You don't have to apologize. I find you very attractive as well."

Dean swallowed hard. "I'm not...very good at talking sometimes."

"I know." Cas nodded.

"Thanks," Dean laughed. "But I mean, I want you to know...how I feel about you."

"I already know."

"Really?" Dean looked slightly horrified. "How?"

"Our bond. I can feel your soul calling for me. I can sense the love you have for me. I just wasn't sure...what kind of love." He said hesitantly.

Dean slid closer to him, until their noses were almost touching. He gently laid a hand on Cas's cheek, and pressed their lips together. It was a soft, chaste kiss, but there was so much _love_ behind it.

"Does that answer your question?" Dean asked, voice rough.

"Yes," Cas said breathlessly.

"Why didn't you say anything?"

"I...didn't want to lose you. I was under the impression that you were strictly heterosexual."

Dean shrugged. "I swing both ways, but I've been in denial for way too long."

"I am glad you've realized this."

"Me too," Dean's eyelids were drooping.

"Sleep," Cas said, tenderly kissing his forehead.

The hunter let himself start to drift, but his eyes sprung open after only a few seconds.

"Cas," He whimpered. "I can still see their claws."

"Shh," Cas pulled him closer, until Dean's head was resting against his chest.

"I can feel your heartbeat!" He said with wonder. "I thought you didn't have one."

"My vessel is still human," Cas smiled. "I maintain respiration and the circulation of blood throughout the body."

"So, in English, you still breathe and have a heartbeat."

"That was English." Cas said, confused.

Dean chuckled. "You're adorable." He yawned.

Cas gently ran his fingers through the hunter's soft brown hair. "You are quite endearing as well."

"Mmm," Dean mumbled something that sounded vaguely like a protest, but was soon fast asleep in Castiel's arms.

He hadn't been lying when he said watching Dean was never boring. From this angle he couldn't see the hunter's face, but he could feel every breath. Every sleepy sigh. He continued to stroke the hunter's hair, marveling at how soft it was.

He could stay like this forever.


End file.
